Ceramic liners are presently used in chutes, hoppers, bins, and other material handling equipment where abrasive or corrosive material would cause such rapid wear that a bear metallic surface would be impractical. A form of ceramic known as "weldable tile" has been used in panels for lining surfaces subject to unusual abrasion. The panels generally include ceramic tiles or blocks fixedly secured directly to a steel substrate by welding. Metal fasteners carried by or retainers carriable by individual tiles are welded to the steel supporting substrate to thereby directly secure each of the tiles. Alternately, ceramic tiles are known to have been cemented or otherwise directly bonded to a supporting substrate, as with polyurethane, Portland cement, epoxy, polyester or silicone based adhesives.
The ceramic tile available for use as a wear resist liner is especially brittle, being particularly susceptible to chipping and breakage when directly affixed to a rigid structural substrate. Premature tile failure frequently occurs in material handling applications where, in addition to surface sliding, surface impacts are present.
One approach at minimizing tile damage in impact applications has been to use tiles whose individual surface area is relatively small. This construction has proved to be labor intensive and thereby costly, and only indirectly addresses the problem of tile damage and dislodgement. Furthermore, liners are known to have been combined with a cushioning substrate so as to form replaceable composite panels which provide areas of coverage in both sliding and impacting contact with such materials as ore, crushed rock, coal, concrete, grain and other abrasive aggregates typical of the mining, foundry, milling and other material handling industries. However, heretofore the structural integrity of such shock absorbing composite wear panels has proven to be suspect and problematic, resulting in premature replacement of either tiles, or in most cases whole panels. Aside from the direct capital costs, unacceptable downtime and losses are typically associated with repair/replacement.
Abrasive resistant ceramic liners, usually in the form of discrete ceramic tiles, have proved difficult to secure to a cushioning substrate so to form a durable panel capable of enduring repeated surface impacts and vibration as applications typically require. Although various primers, pre-treatments and adhesives are known, their use for securing ceramic tiles to various cushioning substrates is complex and costly, often times requiring carefully controlled application steps and conditions so as to avoid unpredictable and ultimately unsatisfactory results. Furthermore, when ceramic tiles are exclusively adhered or otherwise affixed to an adjacent cushioning layer, the structural integrity of such composite structure depends not necessarily upon the bond therebetween but upon the weakest of the several bonds, whether mechanical or chemical, between adjacent layers of the composite structure. The structural integrity of the composite panels is only as strong as its "weakest link". It is the "weakest link" of heretofore known composite panels that proves problematic in applications where vibration in combination with surface impacts has led to deterioration of the composite structure so as to render such structures ineffective for their intended purpose.
Where ceramic tiles are effectively "embedded" in a natural or synthetic rubber, effectiveness is limited as the composite structures are subject to unacceptable wearing due to the abrasive material acting directly on the cushioning material surrounding the ceramic tile. This ultimately results in dislodging the otherwise suitable tiles from the composite structure which is thereby ineffective to the point of requiring replacement. Here the "price" of shock absorption is a significant decrease tile retention and thus panel longevity. This is likewise the case where the ceramic tile is affixed to no more than its adjacent layer in the composite structure.
Accordingly, it is therefore advantageous and desirable to provide a ceramic composite that has the impact resistance of energy absorbing/ceramic composites, yet possesses superior structural characteristics which among other things contributes to a greatly extended wear life.
It is likewise advantageous and desirable to provide a method of anchoring ceramic tiles to a support substrate in a way to nonetheless permit individual tiles the freedom to be compressed with the underlying resilient energy absorbing layer and thereby efficiently distribute impact forces imparted thereto.
Similarly, it is desirous to provide a wear structure wherein ceramic tiles are capable of compressive/expansive movement without being pulled from the composite structure.
It is further advantageous to provide an abrasion, impact and vibration resistant wear panel whose surface area has a maximum ceramic tile coverage area (i.e., fewer large tiles versus numerous smaller tiles).